Cytotoxicity of plant extract on Neuro-2a, Caco-2 and Vero cell lines by using MTT assay and Neutral Red uptake test

The present study was undertaken in order to comparethe cytotoxic effect of five hydroalcoholic plant extracts on Neuro-2a (N2A), Caco-2 and Vero cell lines using MTT (3-(4, 5-dimetylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide) and Neutral Red uptake assay. After 72 hours’ exposure to extracts at different concentrations (1.56 to 500 µg/mL), it was found that Phyllanthus amarus , Vitex doniana , Tectona grandis leaves and Plumeria alba trunk bark hydroalcoholic extracts had no cytotoxic activity on the Vero cells. The concentrations of extract which inhibit 50% of cell growth (IC50) on Caco-2 cells were between 4 and 94.50 µg/mL. P. amarus , V. doniana and T. grandis bark exert a cytotoxic activity on caco-2 with an IC50<30 µg/mL. The comparison of the IC50 of the extracts had shown the following toxicity: P. amarus < V. doniana < T. grandis bark < T. grandis leaves < P. alba. The IC50 values on N2A cell were from 54.16 to 398 µg/mL. By comparing the IC50 of the extracts on N2A cell, the results of plants toxicity were as followed: P. amarus < T. grandis bark < T. grandis leaves < P. alba < V. doniana. It appeared from this study that, P. amarus extract exert the most cytotoxic activity among the plant extracts and Caco-2 cell was the most sensitive cell line among the three studied.